In shoes, the difference in midsole height and forefoot is referred to as drop. It is typically referenced in millimeters. If a shoe has a 10mm drop, the forefoot is placed 10mm below the heel. Standing barefoot, a person has zero drop. There has been more attention placed on shoe drop in the last 10 years, especially in running shoes.
Most shoes have some pitch in their design. When we walk, our heel lands first to the ground before we roll forward. Having some pitch helps remove pressure from the heel bone and facilitates a smoother heel-to-toe transition. Many casual shoes have a drop between 6 and 8mm. Traditionally, running shoes have a higher drop of 10 to 12mm. This accounts for extra heel cushioning to disperse large ground reaction forces.
Drop has little to do with how high you are off the ground. That distance is called stack height. Running shoes designed for maximum cushioning may have a midsole a couple of inches thick but the differential between the heel height and forefoot height may only be 6 millimeters.
Today, running shoes have drops from 0 to 12 mm. When selecting shoes, whether running, work boots, casuals or anything in between, the most important considerations are fit, feel and function. A shoe’s drop can affect all three.
When purchasing running shoes, understanding drop is important. The general rule of thumb is to avoid aggravating your feet by switching from a high-drop shoe a low drop (or vice versa). Big swings can stress the Achille’s tendons and your biomechanics.
What drop is best for you? If you know the drop height of your current running shoes, stay within the range of 2 to 6 millimeters. If you want to try a lower drop, do so incrementally and as part of your training routine until your body becomes conditioned to the change.
There are times where a specific drop can help with an injury. Generally, a higher drop shoe has the potential to load the hips and knees more, while a lower-pitched shoe can place greater stress on the foot, ankle, and lower leg. The inverse is true: higher-pitched shoes can deliver less stress to the upper legs and hips while lower-pitched shoes can be better for the lower leg like ankles and arches. For many people, a lower-pitched shoe has the potential to help manage and recover from common injuries such as ITB syndrome and general knee and hip pain. A higher-pitched shoe could help those suffering from plantar fasciitis, Achilles tendon, and calf injuries. You should always consult a medical professional, but the point is heel drop is an important part of shoe selection.